Question

x^5-x^3-2x^2 is it increasing or decreasing at -2?

Answer 1

are you saying if x is -2?

Answer 2

2x^2 is the same as saying x^4, right?

Answer 3

-2x^2 would be a positive number, if that is what you are asking...

Answer 4

is someone not supposed to differentiate?

Answer 5

i would say it's increasing at -2 if i understand the original question...

Answer 6

thats was my thnking too

Answer 7

@basketmath: No, its not. 2 * 2^2 = 8, while 2^4 = 16.

@mathfrick lolo,
Best way to do this is to differentiate. Differentiation of this is 5x^4-3x^2-4x. At x = -2, it is (5*(-2)^4 - 3* (-2)^2 - 4(-2)) = 76 which is positive. so the function is increasing.

Answer 8

yeah. my thinking was flawed on the 2x^2 equaling x^4. i am trying to focus on too many things. lol. test in a few hours.... i knew it was increasing. my apologies for any confusion.

Answer 9

i knew differentiation was part of it thanx Tai